White spot

I have a huge white spot at the back of my mouth. It is in between my lower and upper back teeth. I can't chew my food properly as each time I chew I am like squashing the white spot. So I just chew abit and swallow the rest. I get this quite often and it hurts. I refuse to use any medication as I'm quite phobia of having stuff stay in my mouth. I will have a tendency to lick it off and swallow it. And I haven't turn to salt either as I am afraid it will cause a bigger hole in the spot. Argh, I can't wait to go home!